Validation of the EuroSCORE in Japan

Abstract

Objectives: Recently, the European System for Cardiac Operative Risk Evaluation (EuroSCORE) is the one of the most confidential risk prediction models of cardiac operations, especially in Europe and North America. But in Japan, we have not yet established Japanese own perioperative risk assessment scoring system. The aim of this study is to assess performance of the EuroSCORE model on the patients undergoing cardiac surgery. Methods: The additive EuroSCORE models were applied to all patients performed cardiac surgery at our institution from 1st June 2006 to 1st July 2007. Observed and predicted mortalities and were compared. Results: Three hundred thirteen patients with complete date were analyzed. Japanese patients were older with proportionately more females. Japanese patients had also more comorbidity (vascular, neurological, and especially renal dysfunction). Japanese patients were more likely to be in 'critical preoperative state', and 'emergency'. Surgery on thoracic aorta had a higher incidence in Japanese patients. Of the 313 patients, there were 13 deaths observed, giving an overall observed mortality rate of 4.15%. The additive EuroSCORE model predicted higher mortality rate of 7.51%. The numbers of patients in each risk groups were as follows; low-risk group (EuroSCORE 0–2) was 44 patients (14.0%) with no death, medium-risk group (EuroSCORE 3–5) was 85 patients (27.2%) with no death, and high-risk group (EuroSCORE 6≥) was 184 patients (58.8%) with 13 deaths. Conclusion: There were significant differences in the prevalence of risk factors between Japanese and European cardiac surgical populations, and we may need to modify the EuroSCORE for Japanese patients.